Research Areas and Research Achievements of Disaster Prevention and Mitigation

Research Area 1 – Railway Disaster Reduction and Route Selection in Complex and Dangerous Mountainous Areas

Completed by: Yao Lingkan, Huang Yidan

Relevant Research Achievements:

To address the threat of natural disasters in the complex and dangerous mountainous areas, the idea of risk control operation throughout the whole process from railway route selection to individual engineering design to realize the dual control of disaster risks in the investment and operation of railway projects in mountainous areas is first proposed; then, as for the areas with frequent disasters, the methods of disaster risk identification and risk control in the design of route selection is put forward; because the evaluation scheme of railway in mountainous areas is characterized by many qualitative and uncertain indexes, and is obviously influenced by macro-economic situation, there are great risks in decision-making, so the optimal models of scheme comparison for route selection of railway based on the deviation projection technology, the utility theory, and the risk theory are presented. Therefore, it is the first time at home and abroad to put forward a relatively complete theory and technical system of railway disaster reduction and route selection in the complex and dangerous mountainous areas, which also plays an important role in modernizing the design method of railway route selection. The results have been applied as a guidance in the route selection design of Dali-Ruili Railway and Chengdu-Lanzhou Railway, and provide a scientific basis for the selection of corridor scheme and local direction scheme in the prefeasibility study of Sichuan-Tibet railway.

Research Area 2–Early Warning of High-Speed Railway Earthquake

Completed by:Yang Changwei

The research group has successively mastered the key core technologies such as P-wave first arrival recognition, single P-wave early warning, and edited or revised six books of industry standards such asTechnical Conditions of High-speed Railway Earthquake Early Warning and Monitoring System, preliminarily constructing the theory of high-speed railway earthquake monitoring and early warning, and completing the development of relevant equipment. During the test period, the line and earthquake early warning systems accomplished the successful early warning of the Kangding earthquake on November 22, 2014 and the Jiuzhaigou earthquake on August 8, 2017, with a cumulative number of 132 times of successful early warning for natural earthquakes. The key technical indicators such as false alarm rate and missing alarm rate show that our related technology is significantly better than that of Japan and other countries and we have broken the technical blockade and monopoly of foreign countries.

Research Area 3 – Research on the Setting Input of Ground Motion and Seismic Risk Assessment of Major Projects

Completed by: Liu Zhengping, Sun Xiaodan

Through the ground motion simulation method of integration of hypocenter-path-site condition and BSI inversion technology, the process of earthquake hypocenter rupture is reconstructed; the near-fault strong ground motion field and surface deformation field are estimated; the relationship between near-field strong ground motion propagation and spatial distribution, earthquake source mechanism and site condition is revealed, and the ground motion setting input of nuclear power plant, reservoir and lifeline engineering is constructed. In terms of the earthquake damage mode of the line engineering crossing the fault zone, the program of probability and risk analysis of permanent displacement of the surface is developed, which can provide the prediction of the surface deformation, matching the accuracy of the line survey and design. Based on the simulation of ground motion, the exploration and research on the setting input of ground motion of nuclear power station are carried out, and the earthquake source mechanism and activity analysis of the earthquake in the Three Gorges Reservoir Region is completed.

The Slip Distribution of Fault Surface of Oklahoma Earthquake in 2011 Focal Depth Location Map of Earthquakes in the Three Gorges Reservoir Region

Research Area 4 – Performance Degradation Mechanism of Engineering Structures and Multi-scale Research on Disaster Control

Completed by: Wang Jian

In terms of the deterioration of wheel rail performance caused by the long-term interaction of heavy-duty railway’s wheel and rail, the idea of using the material processing method to set nano crystalline gradient functional material on the wheel rail surface to enhance the mechanical strength of the contact surface while maintaining enough toughness is put forward for the first time so as to control the wheel rail fatigue wear, and the optimization design scheme of wheel-rail surface gradient functional structure is presented. Based on the multi-scale research framework, the optimal design scheme can provide a reference for the study of wheel rail structure performance degradation mechanism and disaster control.

In terms of the dynamic characteristics and dynamic response of soil-structure interaction and soil-tool interaction, a three-dimensional continuous-discrete coupling simulation method is proposed, which fits for the multi-scale simulation of foundation reinforcement by dynamic compaction and piles thrusted-expanded with column-hammer, and the multi-scale research of site-structure interaction during earthquake.